anderson



(No Model.) 3 Shets-Sheet 1.-

A. ANDERSON.

NON INTERFERING STREET BOX- FOR FIRE ALARM TELEGRAPH SYSTEMS. No. 354,761. PatentedDec. 21, 1886.

Wt'bmsscs. I i I N. PETERS, PhnmLithagrnphor. Washinglon. n.;c.

3 Sheets-Sheet 2.

(No Model.)

4 A. ANDERSON. NON INTERPERING STREET BOX FOR FIRE-ALARM TELEGRAPH SYSTEMS.

N0. 354,761. Patented Dec. 21-,1886.

avwewtoz @313 M aH'OzMm s W-L-kmeoaeo 67419 ur. Warhington. D. C.

(N0 M deI.) 3 SheetsSl1ee't 3.

A. ANDERSON.

NON INTEEEE ING STREET BOX FOR FIRE ALARM TELEGRAPH SYSTEMS.

' No. 354,761. Patented Dec. 21, 1886.

.. X %MEC-CZ%M% I N. PETERS. Fhnlo-lllhognphu. Whhingiun. D. C.

NITED STATES PATENT Fries.

ALEXANDER ANDERSON, OF TORONTO, ONTARIO, CANADA.

NON-INTEBFERING STREET-BOX FOR FlRE-ALARM-TELEGRAPH SYSTEMS.

EPECEPICATION forming part of Letters Patent No. 354,761, dated December 21, 1886.

Application filed February 6, 1886. Serial No. 191,050. (No model.) Patented in Canada February 13, 1886, No.23,411.

To all whom it may concern:

Be it known that LALEXANDER ANDERSON, of the city of Toronto, in the county of York, in the Province of Ontario,O-anada, electrician, have invented an Improved N on-Interfering Street-Box for Fire-Alarm-Telegraph Systems, (for which I have received Letters Patent in Oanada,No. 23,411,February 13,1886, )of which the following is a specification.

The invention relates to that class of firealarm box in which thestriking mechanism is wound for action when the starting-hook is pulled upon; and the object of the invention is to prevent more than one box operating at the same time.

It consists in providing each box with mechanism so arranged in the fire-alarm telegraphic circuit that the opening of a box while any other box in the circuit is striking disconnects the winding mechanism from the starting-hook, thereby effecting the object of my invention, substantially as hereinafter explained.

Figure 1 is a perspective view of a firealarm box, showing the doors open and sufficient of the mechanism to indicate my invention. Figs. 2 and 3 are diagrammatic views of some of the parts in two positions. Fig. 4 is a side elevation showing. the connections with the magnet F. I

As the construction of the fire-alarm box upon which mine is an improvement is well understood, it will not be necessary for me to explain in detail its entire construction. It will be sufficient to say that it is worked under a closed-circuit system, and that A represents the crank by which the striking mechanism. is wound.

a is the'notch formed on the end of the crank A to receive the end of the pawl B. This pawl is pivoted upon the sliding bar G,held in suitable bearings on the inner door, D, and to which the hookE is attached. When the hook E is pulled down, the end of the pawl B enters the notch a, (see Fig. '2, in which the pawl is shown in dotted lines,) and the crank A is turned so as to wind up the striking mechanism. The object of 1 this mechanism is to start the striking mechanism within the box andto prevent the said box being interfered with when once started until the first series of alarm has been sounded; but in this class of fire-alarm boxes the striking can be interfered with by the opening and starting of another box, and it is to prevent this latter interference which is the object of my invention.

F is an electromagnet placed in the same circuit as the electro-magnet which operates the bell within the box.

G is a hanging bar, pivoted at b, and having attached to its free end the armature H and push-bar I.

J is a finger attached to the outer door, K, and extending,when the outer door is closed, through a hole, (I, inthe inner door, D, so as to project below the armature H and hold it in contact with the electromagnet Fv as long as the outer door remains closed.

In the class of fire-alarm box upon which my invention is an improvement, when the outer door, K, is opened,the circuit on which the striking-bell of the box is placed is brought into the main circuit. Consequently, as I have placed my electro-m'agnet F in the same circuit as the bell-circuit, the opening of the box instantaneously charges my magnet, making it sufficiently powerful to hold the armature H in contact with it after the supporting-finger 1 wire L, and follows the course indicated till it reaches the key. Now, when the alarm-box is open, the current of electricity passes through the wires N O P to the electro-magnet F,"

thence back over the wire S to the pivoted lever 19, where it is connected by the wire R to the line-wire M. If the door is closed, however, the rod 2' is pressed back, and brings the upper portion of the lever h against the spring 9'. The course of the current is consequently changed, and now passes from the line-wire L over to the wire Nto the key, thence over the wire Q through spring j, lever h, and over the wire R to the line-wire M. It will thus be seen that the electro-magnet'F is thrown into circuit immediately on the opening of the door K.

\ When the striking mechanism is wound up,

it immediately commences to operate, making and breaking the current for the purpose of striking the bell, and the current passing through the electro-magnet F is likewise made and broken. Consequently, as the pivoted hanging bar G is sufliciently heavy to fall by its own gravity when unsupported, the armature H, attached to it, will naturally fall away from the magnet F the instant that the our rent is broken, and the push-bar I is thus carried beyond the end of the crank A, as shown in Fig. 3, which prevents the pawl B from engaging with the notch a. This actiontakes place within the box which is being operated,

and as the opening of the outer door of any other box in the fire-alarm circuit will bring the electro-magnet F within it into the main circuit, it follows that the opening of the outer door of any other box in the main circuit will instantly, as the current breaks, cause the armature H to fall clear of the electro-magnet F, and, as in the case already described, places the push-bar I in position, so as to prevent the pawl B coming in contact with the crank A, thereby rendering it impossible to start,

more than one box at the same time in the same circuit.

It should be noticed that the armature H not only falls away from the electro-magnet, but'it also falls beyond its field, so that the momentary passage of the circuit through said electro-magnet will not of itself raise the armature, but when the outer door is closed the finger J passes beneath thearmature, bringstriking mechanism may be wound up by pull-' ing upon the hook E, thus causing the pawl B to bear on the crank A, as shown in said Fig. 2. V

In order to prevent the hanging bar G falling below the finger J, I provide a hanger, L, having asmall adj ustingset-screw, e, by which the fall of the hanging bar G can be easily regulated.

With the view of holding the pawl B steady, I place on the slide 0 a small spring, f, arranged to act on the pawl B, as indicated, and hold it against the stop g.

I am aware that it has been proposed to prevent the sending of interfering alarms by means of a central repeater, which reverses the polarity of the currents on the various lines and operates a block, which block locks the mechanism when another signal is going in; but, so far as I am aware, it has never been proposed to disconnect the winding mechanism from the starting-hook by the opening of use, an electro-magnet within the box to interpose said device, and circuit-changing connections, substantially as described, to operate said magnet by opening the door to the starting-hook,whereby a signal is only transmitted when the line is free, as set forth.

2. A pivoted hanging bar, G, having a pushbar, I, and armature H, attached to it, in combination with the pawls B and the independent electro-magnet F, connected to the firealarm telegraphic circuit,.so that the opening of the box shall charge the magnet F, substan- 8o tially as and for the purpose specified.

3. The pivoted hanging bar G, provided with push-bar I and armature H, and an elec-- tro-magnet, F, connected to the fire-alarm tele graphic circuit, as specified, in combination with the finger J, attached to the door K, substantially as and for the purpose specified.

4. The pivoted hanging bar G, provided with push-bar I and armature H, an electromagnet, F, connected to the fire-alarm tele- 0 graphic circuit, as specified, and a finger, J, connected to the door K, in combination with the hanger L, provided with the adjusting setscrew 0, substantially as and for the purpose specified.

5. The slide 0 and the pawl B, pivoted thereto, in combination with the spring f and stop 9, substantially as and for the purpose specified.

6. The combination, with the magnet F, pivoted hanging bar G, armature H, and pushbar I, carried thereby, of the hanger L and finger J, substantially as described.

Toronto, January 30, 1886.

ALEX. ANDERSON. In presence of- CHARLES C. BALDWIN, J. M. JACKSON. 

